Equipment 101: Palletizing equipment
June 01, 2011 - MMH Editorial
Strong, stable, secure. These are important qualities in a palletized load. While palletizing is the science of placing and securing units or containers on pallets, it can be somewhat of a materials handling art form.
“If product is going to move, it has to be in an easy to handle unit load,” says Fred Hayes, director of technical services for the Packaging Machinery Manufacturers Institute (PMMI). “If it’s not on a pallet, it’s not going to go very far,” Hayes adds.
Of course, product is moving all the time and often has to go very far before reaching its destination. But getting it there is only half the battle; the other half is getting it to the final consumer in an appealing, salable condition. Enter palletizing equipment.
From basic assist equipment that works in manual operations to sophisticated robotic technology, here’s a look at a few palletizing solutions.
Manual palletizing can be done by people and without any mechanical assistance at all. However, there are simple solutions that can aid in the process.
Backboard: Since product placement on a pallet is important to the load’s structure, a backboard can be used to guide the loading process. Typically about 4 feet long and 6 feet high, a backboard is made of steel and welded together in a 90 degree angle, explains Dan Johnson, product line manager for palletizing for Brenton, a division of Pro Mach. It’s a simple alignment aid that means workers spend less time lining up the product as they build the load, he adds.
Lift assist and positioning: Manual palletizing can also be facilitated with assist devices like powered lift tables or work positioners that are specifically designed for palletizing functions.
Using calibrated springs or pneumatic devices, pallet positioners automatically adjust the height of the pallet load. Pallet positioners can be topped with turntables so that operators can stay in one place and rotate the load rather than waste time and steps walking around to build the pallet.
In some palletizing stations, when a pallet layer is complete, the operator lowers the work surface as required to maintain a comfortable working height.
Because positioners can hold up to 4,500 pounds, lift trucks are required for depositing and retrieving pallets.
There are physical and ergonomic challenges when you are palletizing manually. In addition, it’s difficult to attract and retain enough labor to keep an operation moving smoothly. Semi-automatic or automatic palletizing, with machines or robots, can eliminate the risk of ergonomic injuries to workers and reduce operator error.
Semi-automatic palletizing equipment, which is popular in niche markets where products are heavy and difficult to palletize manually, can handle up to 20 bags or cases per minute. This equipment is well suited for low-speed operations that can’t justify the cost of full automation but require a solution to help prevent worker injury.
In one style of a semi-automatic palletizer, a conveyor delivers product to an operator who arranges it into a layer on a plate. Then, with the press of a button, the plate surface retracts, allowing the layer of items to drop onto the pallet just below. The plate can be made of smooth metal, slippery polyethylene, rollers or even an air table for especially heavy products.
In another example, an operator receives product on a conveyor at an ergonomic workstation. A mixed-case pallet is built on a lift that the operator lowers as required to maintain a comfortable working height, explains Ken Ruehrdanz, warehousing and distribution market manager for Dematic.